FTC is expected to soon grill Mark Zuckerberg in Meta's antitrust trial

• On Monday, one of the most highly consequential antitrust trials in years began in Washington.
• In Federal Trade Commission v. Meta Platforms, the FTC says the social media giant boxed out competitors.
• Meta argues that it is a source of innovation and has not violated US antitrust laws.

Meta boss Mark Zuckerberg is expected to be called as the first witness in the US government's blockbuster antitrust case against the social media empire as soon as Monday, an attorney for the Federal Trade Commission said.

Daniel Matheson, the lead lawyer in the FTC's lawsuit against Meta, revealed the anticipated scheduling of Zuckerberg's testimony as the trial opened Monday in a federal courtroom in Washington, DC.

The FTC is expected to grill Zuckerberg for as long as seven hours, according to court papers filed earlier by the government agency.

The government's case against Meta comes after a yearslong probe into whether the social media behemoth violated US competition laws when it acquired Instagram in 2012 and WhatsApp in 2014.

In the trial, FTC regulators want to force Meta to spin off the two services. If it succeeds, it would be a major blow to Meta's business. Instagram and WhatsApp both have over 2 billion active users, according to the latest available data from those companies.

The government also plans to call former Meta Chief Operating Officer Sheryl Sandberg to the witness stand, along with Adam Mosseri, the head of Instagram.

Matheson said that he would ask Zuckerberg about a 2012 message he sent to Sandberg. The FTC lawyer said the email shows Zuckerberg's unfiltered thinking about the social media marketplace.

"'Messenger isn't beating WhatsApp. Instagram was growing so much faster than us that we had to buy them for $1 billion… That's not exactly killing it," Zuckerberg wrote, according to a slide presented by the FTC.

The FTC argues that Meta's acquisition of Instagram and its acquisition of WhatsApp were intended to box out competition and dominate the social media sphere. The government says these acquisitions were part of Meta's "buy or bury" plan to maintain market dominance.

"Meta has for many years reaped massive economic profits beyond what you would expect to see in a competitive environment," Matheson said in his opening statements.

The FTC lawyer added, "We're going to show contemporaneous records, they are going to show self-interested executives and paid experts."

Regulators say Meta's business strategy breaches existing antitrust laws, and the FTC is hoping to force Meta to divest both Instagram and WhatsApp to ease the company's grip on the industry and afford smaller companies the opportunities to attract more users and potential advertising dollars.

Meta argues that the company has been a fair actor and a beacon of innovation in the social media marketplace.

"The evidence at trial will show what every 17-year-old in the world knows: Instagram, Facebook, and WhatsApp compete with Chinese-owned TikTok, YouTube, X, iMessage, and many others," Meta spokesperson Christopher Sgro said in a statement. "More than 10 years after the FTC reviewed and cleared our acquisitions, the Commission's action in this case sends the message that no deal is ever truly final."

Meta attorney Mark Hansen argued in his opening statements on Monday that the government's case amounts to a "grab bag of FTC theories at war with the facts and at war with the law."

Hansen said it was "remarkable" that the FTC never once mentioned TikTok in its 95-minute opening arguments.

"If people want a substitute for Instagram and Facebook, they go to YouTube and TikTok," Hansen said, adding, "More than 100 million more Americans use WhatsApp and they don't pay a cent, after Meta made it free."

FTC case against Meta began in 2020

The FTC's case first began at the end of President Donald Trump's first term in 2020 and forged ahead under former President Joe Biden's antitrust team.

The dynamic between Trump and Zuckerberg has shifted demonstrably since 2020, however.

After the Capitol riot on January 6, 2021, Trump railed against Meta's decision to "indefinitely" suspend his Facebook account. In January 2023, Meta reinstated Trump's Facebook and Instagram accounts, and in July 2024, the company lifted "heightened suspension penalties" that had also been in place.

In the 2024 election cycle, Trump gained increased political influence within Silicon Valley. After Trump won a second term in November 2024, Zuckerberg quickly congratulated him on his victory.

Meta also donated $1 million to Trump's inaugural fund, and Zuckerberg was a high-profile guest at the president's January 2025 inauguration. The Meta CEO has visited the White House multiple times since Trump began his second term.

April 14, 2025: This story is developing and will be updated.